Having sorted out most of the bikes electrics I tried the starter and found that it has a distinct "bark" as is slows to a stop. I am guessing that there is some kind of sprag clutch or splines in the starter and the bark come from engagement and/or disengagement. Maybe a lack of lubrication or corrosion? The bike sat for ten years so I am not surprised that there might be some corrosion in the moving parts. Is there anything that I can do or check from the outside of the starter, without having to removing it? Is it likely to quieten down with some more regular use? I looked at the parts diagrams and it seems like there are three Allen bolts holding it in place. Two are relatively easy to get at, the third looks like I have to take off the stator and a gear or two in order to get to the bolt head. If anyone has any advice about removing and refurbishing the starter, I would be grateful. I would like to avoid removing the stator and gears, but obviously will if that what needs to be done.
The sound you describe sounds more like the starter clutch than the starter motor, you might be able to differentiate with a screwdriver or stethoscope, plus a starter motor giving bearing or mesh problems would more likely have a constant sound during operation . The starter clutch is housed within the assembly of the alternator/flywheel. If it is the starter clutch then it’s unlikely to get better and if noticeably loud and prolonged then is usually the sign that it might need replacing soon, hard to say without hearing and also they can battle on for ages with this sound and particularly as yours takes less effort to churn over then some of the larger, high compression bikes that can fail more quickly as a result.
Many thanks for the insight Chris, your comments are very helpful. In removing and looking around inside the LH cover I noticed that the locking washer under the rotor nut has a chunk missing where a folded up section had broken off. Now there is nothing to stop the nut rotating off the end of the crank. Why I didn't notice this when I was working on the ignition pick ups escapes me, but I should replace the washer and fold up a new lock tab. With regard to the starter bark, I should remove the rotor and check out the starter clutch. If that all looks good, I guess it is a pretty easy to pull the starter and have a look inside. My next issue is to try and work out a way of securing the rotor/crank so I can undo the nut. Do you know a cunning trick to do this, or do I have to fabricate something.....?
re: undoing nut, if you can buy or get access to one of these:- https://www.toolshouse.co.uk/produc...JUb_gHmNy_2qO3W89NOJVBonYjz7xYDEaAm0REALw_wcB (there is also an identical clone on EBay that is even cheaper) then the almost immediate torque is enough to undo the nut without needing to restrain anything, just make sure spark plugs are in to help, and if you either centre-pop or Tippex the nut and the shaft for alignment purposes, you can do the nut back up in the same manner. It's worth using a "tough" Loctite here, my memory fails me, so have a search (223?) Re: Electric Impact gun, you won't regret buying it, it's an incredibly useful piece of kit, I was used to using pneumatic equivalents and couldn't believe that 13 amps was capable of such useful torque.
It's up to you re: starter sprag noise - you could put a video/Youtube video up? I wouldn't go dismantling the starter unless you have a strong hunch that it is the cause of the noise.
That's interesting Chris, so you don't need to fabricate the special Ducati tool (88713.0108...), you can just use this torque wrench to break the nut loose? I like the idea of indexing the nut before removing it. I have had to make a few ring-style tools to secure clutch baskets and the like over the years (use once and then never need again..) and its always a time consuming PITA...
I am going to investigate further before I dive too deeply into the engine. I do need to replace that damaged locking washer though. I suspect the bark may just be the result of the bike sitting for ten years. I will cycle the starter a few times with the plugs out and see if anything changes. Many thanks.
Yesterday, after much cursing, I gave up on trying to undo the rotor nut on the end of the crankshaft. Despite the creative use of cheeter bars it was so incredibly tight I was likely to do some serious damage to me or the bike if I kept going. I ended up drilling the nut and splitting it in order to get it off. There was no evidence of Loctite, but the tab washer was pretty chewed up. Once removed, I pulled the rotor and the sprag clutch. I removed the gear that meshes with the starter, removed the Allen bolt that the gear had obscured, and pulled the starter. When I opened it up it was very dusty inside. The brushes are probably 30% worn, the commutator ring is significantly dished and needs to be dressed flat. There was considerable end float and the three shims that sat under the rear bush look like they are not in contact with any part of the assembly. The starter has had the bushes replaced at lease once (looking at the soldering job) and you can see where someone has wiped the inside of the case to clean up dust and debris. The front bearing looks in good shape, however the bush under the end cap is very dry and worn out. There is significant end play on the shaft so I am going to replace the bush and hopefully that should stop the bark. I am going to make a replacement bushing so I can fine-tune the end play. As a guide, does anyone have a value for the end play on the starter motor shaft? Appreciate any insight.
I think you have already sussed out the problem the bush sounds as if it is dry, if it is not worn give a small smear of grease that should stop the "bark" when stopping. Sam
You are right Sam. The new bush and some grease solved the bark. When everything was cleaned up I found the previous owner had drilled a very small hole into the back of the original bush, probably to be able to introduce some lube without having to disassemble half the bike....
